textproduct: Quad Cities

KEY MESSAGES

- Chances for storms this evening for portions of the area, as the battle between heat and convection continues (and will continue through at least mid week). Daily severe storm risks also continue with high instability possibly through at least Tuesday.

- A Heat Advisory is in effect today for the southern half of the area with heat indices near 100 or higher. Depending on clouds and storms, Monday may be just as hot.

- Cooler temperatures may occur later in the week and into next weekend if the warm dome of air can get shunted off to the southwest.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 244 PM CDT Sun Aug 9 2026

Following showers and isolated storms this morning, skies have mostly cleared, as seen on visible satellite imagery. This, combined with strong WAA into the region, has helped us to quickly become hot and humid this afternoon. As of early this afternoon, a warm front is draped along the Interstate 80 and Interstate 88 corridors, with gusty winds south of the boundary allowing for some relief amidst forecast heat indices in the low 90s to near 100 degrees. A Heat Advisory is in effect until 8 PM this evening for areas along and south of Interstate 80.

The notable forecast challenge this evening is the potential for thunderstorms. Overall, the chances for thunderstorms has decreased due to a cap that extends from 850-700 mb. Still, a low chance (20- 40%) of thunderstorms is possible from 7 to 11 PM this evening, primarily east of the Mississippi River and along and south of Interstate 80. If storms are able to develop, there is sufficient shear and instability to support supercells capable of all severe hazards.

Heat and humidity will continue on Monday as the warm front remains draped across the area. While the NBM maintains a 40-80% probability of exceeding heat indices of 100 degrees south of Interstate 80, there is some uncertainty due to the potential for showers and storms as another disturbance passes through the flow. As such, any heat headline decisions have been left to the midnight shift.

With the passage of another vort max on Monday, chances for storms appear most likely in the afternoon and evening. However, capping may once again limit any storms in our CWA, leading to development just to our east in northeast Illinois. If storms are able to develop, a similar setup to today would be in place, leading to storms capable of all severe hazards.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 300 AM CDT Sun Aug 9 2026

Tuesday through Saturday...With the flattening ridge transition, the local area may be under the battle zone of the LLVL thermal gradient and upper level short wave propagation path for almost daily chance of showers and storms for much of the week and even into the weekend. This deep summer-like MCS-track for much of the week from the central plains over to the southern GRT LKS and OH RVR Valley may add up to quite a bit of rainfall by Friday. At least temps look cooler by late week and into the weekend as well, with a day or two possibly held down in the 70s with cloud cover and east winds.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1247 PM CDT Sun Aug 9 2026

Prevailing VFR conditions are expected for the TAF period, with chances of MVFR or lower at MLI/BRL/CID in the 10/00-05Z window. Showers are clearing from all terminals at the beginning of the TAF period. There is potential this evening in the 10/00-05Z window for thunderstorms with gusty winds and MVFR CIGs/VSBYs at CID, MLI, and BRL, which has been indicated with PROB30 groups. Of these, highest confidence in seeing storms is at MLI, followed by BRL. Trends this afternoon will be monitored and AMDs issued if confidence increases. Past 10/06Z, the potential for showers will increase.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Heat Advisory until 8 PM CDT this evening for IAZ063>065-067- 068-076>078-087>089-098-099. IL...Heat Advisory until 8 PM CDT this evening for ILZ015-016- 024>026-034-035. MO...Heat Advisory until 8 PM CDT this evening for MOZ009-010.